196,496 research outputs found
Testing the evolutionary link between submillimetre galaxies and quasars: CO observations of QSOs at z~2
No full textWe have used the IRAM Plateau de Bure millimetre interferometer and the UKIRT 1–5 μm Imager Spectrometer (UIST) to test the connection between the major phases of spheroid growth and nuclear accretion by mapping CO emission in nine submillimetre-detected QSOs at z= 1.7–2.6 with black hole (BH) masses derived from near-infrared spectroscopy. When combined with one QSO obtained from the literature, we present sensitive CO(3–2) or CO(2–1) observations of 10 submillimetre-detected QSOs selected at the epoch of peak activity in both QSOs and submillimetre (submm) galaxies (SMGs). CO is detected in 5/6 very optically luminous (MB∼−28) submm-detected QSOs with BH masses MBH≃ 109–1010 M⊙, confirming the presence of large gas reservoirs of Mgas≃ 3.4 × 1010 M⊙. Our BH masses and dynamical mass constraints on the host spheroids suggest, at face value, that these optically luminous QSOs at z= 2 lie about an order of magnitude above the local BH–spheroid relation, MBH/Msph, although this result is dependent on the size and inclination of the CO-emitting region. However, we find that their BH masses are ∼30 times too large and their surface density is ∼300 times too small to be related to typical SMGs in an evolutionary sequence. Conversely, we measure weaker CO emission in four fainter (MB∼−25) submm-detected QSOs with properties, BH masses (MBH≃ 5 × 108 M⊙), and surface densities similar to SMGs. These QSOs appear to lie near the local MBH/Msph relation, making them plausible ‘transition objects’ in the proposed evolutionary sequence linking QSOs to the formation of massive young galaxies and BHs at high redshift. We show that SMGs have a higher incidence of bimodal CO line profiles than seen in our QSO sample, which we interpret as an effect of their relative inclinations, with the QSOs seen more face-on. Finally, we find that the gas masses of the four fainter submm-detected QSOs imply that their star formation episodes could be sustained for ∼10 Myr, and are consistent with representing a phase in the formation of massive galaxies which overlaps a preceding SMG starburst phase, before subsequently evolving into a population of present-day massive ellipticals
The Discovery of Gas-Rich, Dusty Starbursts in Luminous Reddened Quasars at with ALMA
No full textWe present ALMA observations of cold dust and molecular gas in four high-luminosity, heavily reddened (A mag) Type 1 quasars at with virial MM, to test whether dusty, massive quasars represent the evolutionary link between submillimetre bright galaxies (SMGs) and unobscured quasars. All four quasars are detected in both the dust continuum and in the CO(3-2) line. The mean dust mass is 610M assuming a typical high redshift quasar spectral energy distribution (T=41K, =1.95 or T=47K, =1.6). The implied star formation rates are very high - 1000 M yr in all cases. Gas masses estimated from the CO line luminosities cover 1-5()M and the gas depletion timescales are very short - Myr. A range of gas-to-dust ratios is observed in the sample. We resolve the molecular gas in one quasar - ULASJ23150143 () - which shows a strong velocity gradient over 20 kpc. The velocity field is consistent with a rotationally supported gas disk but other scenarios, e.g. mergers, cannot be ruled out at the current resolution of these data. In another quasar - ULASJ1234+0907 () - we detected molecular line emission from two millimetre bright galaxies within 200 kpc of the quasar, suggesting that this quasar resides in a significant over-density. The high detection rate of both cold dust and molecular gas in these sources, suggests that reddened quasars could correspond to an early phase in massive galaxy formation associated with large gas reservoirs and significant star formation
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Properties of the molecular gas in a starbursting QSO at z = 1.83 in the COSMOS field
No full textUsing the IRAM 30 m telescope, we have detected the 12CO J=2-1, 4-3, 5-4, and 6-5 emission lines in the millimeter-bright, blank-field selected AGN COSMOS J100038+020822 at redshift z = 1.8275. The sub-local thermodynamic equilibrium (LTE) excitation of the J=4 level implies that the gas is less excited than that in typical nearby starburst galaxies such as NGC 253, and in the high-redshift quasars studied to date, such as J1148+5251 or BR1202-0725. Large velocity gradient (LVG) modeling of the CO line spectral energy distribution (CO SED; flux density vs. rotational quantum number) yields H{2} densities in the range 103.5-104.0 cm-3, and kinetic temperatures between 50 K and 200 K. The H{2} mass of (3.6 - 5.4) à 1010 Mo implied by the line intensities compares well with our estimate of the dynamical mass within the inner 1.5 kpc of the object. Fitting a two-component gray body spectrum, we find a dust mass of 1.2 à 109 Mo, and cold and hot dust temperatures of 42±5 K and 160±25 K, respectively. The broad MgII line allows us to estimate the mass of the central black hole as 1.7 à 109 Mo. Although the optical spectrum and multi-wavelength SED matches those of an average QSO, the molecular gas content and dust properties resemble those of known submillimeter galaxies (SMGs). The optical morphology of this source shows tidal tails that suggest a recent interaction or merger. Since it shares properties of both starburst and AGN, this object appears to be in a transition from a strongly starforming submillimeter galaxy to a QSO
Thulium laser transurethral incision of the prostate with ejaculation-sparing intent: 2-year follow-up outcomes from a high-volume centre
No full textIntroduction Several 'ultra-minimally-invasive' surgical treatments (uMISTs) have been developed, aiming to relieve benign prostatic obstruction (BPO) and spare ejaculatory function; however, such techniques do not always ensure substantial improvements in uroflowmetry parameters. The aim of the present study was to evaluate the 2 -year functional outcomes of thulium laser transurethral incision of the prostate (ThuIP) as an alternative to uMISTs. Material and methods Data of consecutive patients affected by BPO with indication to surgical intervention and a strong will to spare ejaculatory function were collected on a dedicated prospectively maintained database. A specific "trifecta" was identified as the contemporary presence of: (1) postoperative Qmax >= 15 ml/s; (2) absence of early (within 90 days) complications; and (3) preserved antegrade ejaculation. Results 120 patients underwent ThuIP and were analysed. Median catheterisation time was 2 days (IQR 2-2). Significant improvements in IPSS and IPSS-QoL scores and uroflowmetry parameters were observed at all follow-up times. At the last follow-up visit (24 months) the median Delta IPSS was -12 (-17; -9), median Delta IPSS-QoL was -3 (-4; -2), median Delta Qmax was +7.7 ml/s (+5.2; +11.0), and median Delta PVR was -50 ml (-100; 0) (all p -values <0.001). Fourteen patients reported postoperative absence of antegrade ejaculation (11.7%). Overall, trifecta was achieved in 86 patients (71.7%) at 6 months, in 79 patients (65.8%) at 12 months, and in 75 patients (62.5%) at 24 months. Conclusions ThuIP allows for a significant improvement in uroflowmetry parameters and patient-reported outcomes at 2 -year follow-up. Moreover, antegrade ejaculation is preserved in approximately 90% of cases
TRANSPERINEAL LASER ABLATION VERSUS TRANS-URETHRAL RESECTION OF PROSTATE FOR BENIGN PROSTATIC OBSTRUCTION: A RANDOMIZED CLINICAL TRIAL
No full textINTRODUCTION AND OBJECTIVE: Transperineal interstitial laser ablation (TPLA) is among one of the latest ultra-minimally invasive technique to treat benign prostatic obstruction (BPO). No study investigated the actual rate of preservation of the ejaculatory function after TPLA, in comparison to the reference standard trans-urethral resection of prostate (TURP). We aimed to evaluate the reliability of TPLA in preserving the ejaculation compared to TURP. METHODS: In this single-center, prospective, randomized, open-label study, consecutive patients with indication to surgical treatment for BPO were enrolled between January 2020 and September 2021 (NCT04781049). Randomization defined two treatment arms: Group A: patients assigned to TPLA (experimental); Group B: patients assigned to TURP (standard). Primary endpoints included comparison of visual analogue scale (VAS), change in ejaculatory function (by EJ-MSHQ), and changes in sexual function (by IIEF-5) at 1 month after surgery. Secondary endpoints included ΔIPSS and ΔQoL, and Qmax improvement at 6 months. RESULTS: Fifty-one patients (26 TPLA versus 25 TURP) were analyzed. No differences were found in the perception of pain assessed by VAS. No differences in IIEF-5 score were found between groups. Distribution of ejaculatory function assessed by the EJ-MSHQ remained unmodified after TPLA (p=0.2) while a median 31% decrease in EJ-MSHQ score (IQR -67;-14%) was observed after TURP (p=0.01). Retrograde ejaculation was reported in one patient within the TPLA group (18 patients s/p TURP). A statistically significant difference between the treatment groups was found in terms of postoperative Qmax (15.2 (IQR 13.5–18.3) versus 26.0 (IQR 22.0–48.0) ml/s, TPLA versus TURP, p<0.001). Qmax was statistically significantly improved with respect to baseline after TPLA (%ΔQmax+42 (+24; +76), p<0.001). Both treatments significantly improved IPSS and QoL with respect to baseline, with TURP impacting more significantly (%ΔIPSS -35.9 (IQR -54.5; -1.3) versus -66.7 (-82.8; -46.7) and %ΔQoL -33.3 (-50; -8) versus -60.0 (IQR -80; -33), TPLA versus TURP, all p-values <0.03). CONCLUSIONS: TPLA allowed for maintaining ejaculation in 96% of the cases, confirming to be valid option in patients seeking for pairing the relief from BPO to the high probability of preserving ejaculatory function
Thulium laser transurethral incision of the prostate with ejaculation-sparing intent: 2-year follow-up outcomes from a high-volume centre
No full textIntroduction Several 'ultra-minimally-invasive' surgical treatments (uMISTs) have been developed, aiming to relieve benign prostatic obstruction (BPO) and spare ejaculatory function; however, such techniques do not always ensure substantial improvements in uroflowmetry parameters. The aim of the present study was to evaluate the 2 -year functional outcomes of thulium laser transurethral incision of the prostate (ThuIP) as an alternative to uMISTs. Material and methods Data of consecutive patients affected by BPO with indication to surgical intervention and a strong will to spare ejaculatory function were collected on a dedicated prospectively maintained database. A specific "trifecta" was identified as the contemporary presence of: (1) postoperative Qmax >= 15 ml/s; (2) absence of early (within 90 days) complications; and (3) preserved antegrade ejaculation. Results 120 patients underwent ThuIP and were analysed. Median catheterisation time was 2 days (IQR 2-2). Significant improvements in IPSS and IPSS-QoL scores and uroflowmetry parameters were observed at all follow-up times. At the last follow-up visit (24 months) the median Delta IPSS was -12 (-17; -9), median Delta IPSS-QoL was -3 (-4; -2), median Delta Qmax was +7.7 ml/s (+5.2; +11.0), and median Delta PVR was -50 ml (-100; 0) (all p -values <0.001). Fourteen patients reported postoperative absence of antegrade ejaculation (11.7%). Overall, trifecta was achieved in 86 patients (71.7%) at 6 months, in 79 patients (65.8%) at 12 months, and in 75 patients (62.5%) at 24 months. Conclusions ThuIP allows for a significant improvement in uroflowmetry parameters and patient-reported outcomes at 2 -year follow-up. Moreover, antegrade ejaculation is preserved in approximately 90% of cases
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